You might want to see
perldoc -f srand # PERL random seed documentation.
srand EXPR
srand Sets the random number seed for the "rand" opera-
tor. If EXPR is omitted, uses a semi-random value
supplied by the kernel (if it supports the
/dev/urandom device) or based on the current time
and process ID, among other things. In versions
of Perl prior to 5.004 the default seed was just
the current "time". This isn't a particularly
good seed, so many old programs supply their own
seed value (often "time ^ $$" or "time ^ ($$ + ($$
<< 15))"), but that isn't necessary any more.
In fact, it's usually not necessary to call
"srand" at all, because if it is not called
explicitly, it is called implicitly at the first
use of the "rand" operator. However, this was not
the case in version of Perl before 5.004, so if
your script will run under older Perl versions, it
should call "srand".
Note that you need something much more random than
the default seed for cryptographic purposes.
Checksumming the compressed output of one or more
rapidly changing operating system status programs
is the usual method. For example:
srand (time ^ $$ ^ unpack "%L*", `ps axww | gzip`);
<snip> etc.
You should be able to write similar code in C.
Amish.
Shailesh wrote:
>Good point.
>Caveat: But based on philips advice two pieces of code.
